Why won't my trailer ground??? PROBLEM SOLVED!!! PIC INCLUDED!!

[gunner1]

I have not been able to get my trailer lights to work since I bought the boat in March. I've replaced everything from the harness to the LED lights. At first I thought it was my truck because I checked the factory plug and it would only wok intermittingly. Well, two weeks ago I replaced my 2003 Silverado with a 2007 model and the lights still wouldn't work. So today I decided that I would try to figure it out. What I did was I hooked an extra wiring harness into the truck's factory plug. Next I connected the two green wires on the harness to the probe on a test light and turned on my hazard lights. When I touch the frame of the truck, the light on the test light comes on but when I touch ANYWHERE on the trailer, it don't! I even touched the bunk brackets and everything and still no dice. What could possibly be causing this???

 

[phoenixisrizen]

Re: Why won't my trailer ground???

Re: Why won't my trailer ground???

Do you have the trailer hooked to the truck when you are testing?

The circuit between the truck and trailer needs to be grounded. The battery is grounded to the truck, so to complete the circuit, the trailer needs to either be hitched to the truck or grounded through the plug to the truck.

 

[a70eliminator]

Re: Why won't my trailer ground???

Re: Why won't my trailer ground???

If it's a tilt trailer they can loose ground to the rear half of the trailer, a seperate ground wire or ground strap will remedy.

 

[nhdukes]

Re: Why won't my trailer ground???

Re: Why won't my trailer ground???

I have had this problem. If it is a tilt trailer as a70eliminator asked what happens is rust builds up where the 2 metals meet and eliminates the chance for a good ground. you can run a seperate wire or tilt the trailer and clean up where the 2 metals seat together with a grinder.

 

[gunner1]

Re: Why won't my trailer ground???

Re: Why won't my trailer ground???

Do you have the trailer hooked to the truck when you are testing?

The circuit between the truck and trailer needs to be grounded. The battery is grounded to the truck, so to complete the circuit, the trailer needs to either be hitched to the truck or grounded through the plug to the truck.

Yes sir. It's REALLY weird because each light has it's own ground as well. I know the lights work because if I connect them directly to a 9 volt battery, they come right on!

 

[shepster]

Re: Why won't my trailer ground???

Re: Why won't my trailer ground???

First hook up the trailer to the truck. Next hook up the plugs weather it is a 4 or 5 prong. Now get a Fluke not the test light and measure continuity between the truck and the trailer. Also check where you 4 or 5 prong ground wire hooks onto the trailer and make sure it has a good ground connection.

My trailer has riveted aluminum pieces that become loose and lose ground. Start at the front and work you way back.

Shep

 

[gunner1]

Re: Why won't my trailer ground???

Re: Why won't my trailer ground???

If it's a tilt trailer they can loose ground to the rear half of the trailer, a seperate ground wire or ground strap will remedy.

No, it's a regular trailer. This is really perplexing me. I'm usually very good when it comes to electronics like this but this has me STUMPED!

 

[sjb1962]

Re: Why won't my trailer ground???

Re: Why won't my trailer ground???

On the truck, be sure there is a ground wire from the plug to the frame. Don't trust the factory plug and wiring especially since you bought the truck used. Any RV dealer with a service dept. can test the plug, wiring and ground on your truck cheap.

On the Trailer, the same thing. Make sure there is a wire from the plug to the frame. Grounding thru the hitch is not the way to go.

On a 4 way flat plug the white wire will be the ground wire and should connect to the frame. Then make sure your lights are also grounded to the frame. If the are LED lights they will have white ground wire in the harness of the light.

 

[gunner1]

Re: Why won't my trailer ground???

Re: Why won't my trailer ground???

On the truck, be sure there is a ground wire from the plug to the frame. Don't trust the factory plug and wiring especially since you bought the truck used. Any RV dealer with a service dept. can test the plug, wiring and ground on your truck cheap.

On the Trailer, the same thing. Make sure there is a wire from the plug to the frame. Grounding thru the hitch is not the way to go.

On a 4 way flat plug the white wire will be the ground wire and should connect to the frame. Then make sure your lights are also grounded to the frame. If the are LED lights they will have white ground wire in the harness of the light.

I have a special plug that plugs into the factory plug to test the lights and they work fine. I had the white wire from the harness to the frame and they didn't work, but thanks for the tips.

 

[roscoe]

Re: Why won't my trailer ground???

Re: Why won't my trailer ground???

Just extend the ground wire to all the lights. It will provide a perfect ground and you will not be relying on hit and miss grounds at multiple locations.

 

[gunner1]

Re: Why won't my trailer ground??? PROBLEM SOLVED!!! PIC INCLUDED!!

I was sitting here trying to figure out my problem when I had a thought: " I wonder if my mounting pole goes all the way doen to the trailer itself?" So I undid the bolt you see right below the "spade" you see in the pic that the light bolts to and !VOILA! The damn thing stops about an inch under the bolt! These poles have PVC over them and I thought it was one piece from the trailer up the four feet or so to the light mount but there a multiple pieces inside the PVC! So I simply ran a wire down the inside of the pole, grounded it to the trailer and PRESTO! LIGHTS! Thanks to all for your suggestions.

 

[DDG53]

Re: Why won't my trailer ground??? PROBLEM SOLVED!!! PIC INCLUDED!!

I Had the same prob for a while..Actually it was the Trailer Side 4 Wire plug application. just make sure that the white has a good ground some were near if the trailer if its painted or coated with something just grind it off with a dremal or sandpaper so it come out shinney. My project made me think really hard. Every time i would turn my signals my trailer light would go off like a hazard lights. Those both had ground wire as well. Hope that helps.